A Little Knowledge
by Nia River
Summary: COMPLETE. Wherein the Mirror of Erised proves to be the ultimate Deus Ex Machina.


**Author's Notes:** A what-if idea that developed into a short fic. Doubtless it'd fail in canon. But that's the beauty of fanfiction, yes? I can say 'screw canon, make my nifty idea work'. Hope you like. Gen, no ships

* * *

 _"It shows us nothing more or less than the deepest, most desperate desire of our hearts."_  
– Albus Dumbledore, on the Mirror of Erised

* * *

Harry wasn't sure what he was thinking. It was just a wisp of an idea, really. It was ridiculous and it probably wouldn't work. And yet, still, he found himself venturing to a certain corridor on the third floor that he'd not visited since his first year.

Fluffy's chamber looked huge without the Cerberus squashed inside. The devil's snare had been removed, but he'd anticipated that possibility and brought his broom, so it was easy enough to fly down. The charmed keys were gone, as was McGonagall's chess set and the troll. Snape's puzzle was missing too, along with the fires that had flared up last time he entered the room.

"Well, this isn't promising," Harry mused. "If everyone else has cleared theirs out …"

And then he stepped into the last chamber and was relieved. All the other items might have been removed, but for some inexplicable reason the Mirror of Erised was still in place.

When Harry stepped in front of it, the image was _mostly_ the same as last time. He was older now, of course, but those were still his parents standing behind him proudly. That one big difference was that Sirius was there now too, looking hearty and hale and as though he'd never spent a day in Azkaban.

It was all his family, together and happy.

Harry's head was still throbbing dully, reminding him of why he'd come. His headache was a constant, low-level pain these days; ever since he started learning Occlumency. The only exception was when it flared up into spikes of agony after each new lesson.

He wasn't learning and he knew it. He didn't know if it was his own lack of skill or Snape's poor teaching. It didn't matter which, though, because the result was the same. But his plan, his ridiculous plan, could help him there. Maybe. Possibly.

"Probably not," he admitted aloud, because yes, this was a longshot if ever there was one. "Still, can't hurt to try, right?"

Harry bowed his head and closed his eyes, and then he focussed all he had on a particular _desire_.

He wanted to learn Occlumency.

No, he _needed to know_ Occlumency.

He focussed on that need, dwelled on it, obsessed over it, until it felt like the most desperate desire of his heart.

And then he looked into the mirror … and sighed.

Nothing.

It hadn't changed.

But Harry was nothing if not stubborn so he closed his eyes and tried again … and again … and again. Just as he began to give up hope, there was a flicker. Just a _tiny_ flicker. He didn't see of what, precisely, but he was sure the image had changed.

"It _can_ be done," he realised, determination at once renewed. "I just have to try harder. Keep my focus."

It was another two hours before Harry managed to get the new image back and get it to stay.

His family was gone; it was just him standing there. He wore the same clothes, same glasses, same everything. Except … he didn't look tired and pained as Harry so often did lately. Rather, there was a pleased smile on his face.

Harry's breath caught. Had it really worked? And if it had, would the next part of his plan, the craziest part, work also?

"One way to find out," he told himself. He raised his wand and pointed it at his mirror-double. " _Legilimens_."

The Legilimency spell worked based on emotions. If one imagined their mind as a filing system, each memory would be cross-filed under whatever emotions were felt during the event. Naturally, dealing with Snape would engender feelings of resentment and intense dislike. But _succeeding_ against him? That would also make him feel triumphant, perhaps a bit surprised.

He dove into a mind both foreign and not.

 _It was summer before third year and Aunt Marge had just called his mother a 'bitch' in a roundabout way and Harry was simmering with his hatred of her and so frustrated that he had to put up with it if he wanted that form signed for Hogsmeade but then the unexpected happened and Aunt Marge was suddenly inflating and floating away and Vernon and Petunia were yelling and Harry was shocked but also viciously satisfied and_ —

Harry pulled back with a gasp. The image had faltered again, his concentration shot, but he didn't care.

"It worked," he whispered faintly. Then, a disbelieving smile creeping over his face: "It worked! I can't believe it _worked!_ Wrong memory, but not _all_ wrong. It fit the emotions I was searching for. I just need to keep trying. This is really going to work." He closed his eyes and focussed on his desire once more, then opened his eyes and flourished his wand. " _Legilimens!_ "

 _He was young maybe eight and it wasn't fair because Dudley had swapped their homework and the teacher refused to believe Harry even though it was clear the handwritings didn't match and she called him a horrible little liar because she believed Aunt Petunia's claims and he really didn't like her for that and then he gasped in surprise because her perfectly dyed blonde hair was an awful shade of neon blue and she screamed and Harry grinned because she so deserved it and_ —

"Not that one either," he panted, catching his breath. "This is harder than it looks. Third time's the charm, maybe? _Legilimens!_ "

 _Snape was looking at him over his wand his dark eyes glittering with malice and Harry was not looking forward to this because Snape hated him and the feeling was pretty mutual but then the professor ordered him to "Clear your mind" and before he could so much as blink Harry heard "Legilimens!" and then there was someone else in his brain and he scrambled to 'clear his mind' and somehow probably quite by accident he tripped over the answer and his mind was serene like when he was flying purely for fun and there was nothing in existence but him and the sky and just like that the presence was gone and Snape's face was scrunched up in frustration and he yelled "LEGILIMENS!" again and it was harder but Harry knew what he needed to do now and Snape got no purchase and Harry felt a thrill of victory as Snape snarled at him that the lesson was over and to get out_ —

Harry was gasping from the effort and laughing in success all at once.

"It did it!" He collapsed on the stone floor, beaming at his mirror-self who now surrounded by family once more. "I know how. Clear your mind, serenity … _flying!_ It makes perfect sense now that I've 'experienced' it."

* * *

Needless to say, Professor Snape was shocked by the sudden and inexplicable progress Harry showed at his next 'remedial potions lesson'. He tried again, throwing his all at the attack, but Harry was serene, mentally flying through endless sky.

"The lesson is over," Snape hissed resentfully. "Get out!"

The professor slammed the door behind Harry, who let slip the grin that had been straining to break free.

"Brilliant," he declared to himself. Then he frowned thoughtfully as he wandered back up from the dungeons. "I wonder … are there other things I could learn from the mirror? Things that could help against Voldemort?"

* * *

He'd lucked out on his first effort. Memories that combined resentment, dislike, surprise and triumph were fairly rare; it was a unique emotional cocktail. Also, learning Occlumency was mostly about realising a state of mind. It was complicated to figure out, but simple once you hit on the answer. Legilimency sufficed for this, letting you experience another's episodic memories from their point of view. But that _wasn't_ enough for most other things Harry tried to learn.

"What's the point of trying if all I get is experiences of watching lessons, reading books and practicing spells?" he asked his mirror-self who was ignoring him, chatting with his father. "Yeah, the study part goes a bit faster, but in the end _I_ still have to do the hard work to understand all the information. I can as easily do that _without_ a magic mirror. What I need is a way to transfer actual knowledge and comprehension, rather than to experience memories."

But how? Surely if such a spell was well-known he'd have heard of it. The same if it was _less than_ well-known, if only because Hermione would have found it. Hermione! Now there was an idea. She remained the best person to go to when you needed research done. Except …

"I don't want to share this," he muttered, watching his mirror-self and mother laugh as Prongs and Padfoot romped about. "She'd probably say it's cheating. Or what if she decide it's dangerous, tells McGonagall like she did with the Firebolt? Dumbledore might remember he left it here and hide it away and then this advantage of mine will be lost forever."

If only there was a way to get the results of Hermione's research without _actually_ telling her.

Oh. Right. Harry smacked himself in the forehead. He was an idiot!

Eyes closed, he submersed himself in the desire to know a spell to transfer knowledge and understanding. He made that desire everything that he was, and opened his eyes.

'Look,' his mirror-self mouthed, holding up a book.

Harry shuffled forward, eyes intent on the words. His mirror-self obliged him by turning the pages when Harry made a gesture for him to do so. Once he finished reading he sat back, taking it in. He peripherally noticed that his godfather and parents had returned and the book was gone, but paid it no mind. He was too busy contemplating the directions, tips and cautions about the spell.

'Memoria Transfero' was the incantation. Simple enough. The wand movement was a bit tricky though. It had a twist-reverse-twirl combo at the beginning, and two different options to finish depending on whether you wanted to confirm the transfer or rescind it. That would probably take some practice, but he'd manage. It was the warnings that had him worried. Things like ' _If miscast, the spell can cause too rapid a rate of knowledge transference. Consequences may include migraines, bleeding from the eyes, ears and nose, unconsciousness, bursting of blood vessels in the brain, catatonia …_ ' There were also similar dangers posed to the target of the spell, which was less of a worry considering his target wasn't a real person.

Well, needless to say, Harry was wary. The book had also included some suggestions on how to avoid such a fate. It advised practicing on animals to start with, because their minds were simpler and less likely to overwhelm the caster. Young ones preferably, because they also had fewer accumulated experiences.

* * *

Harry spent a few days wondering where he could get young animals that no one would miss. Then he remembered that he had a mirror which could call up a mirage of anything he wanted. If he _desired_ test subjects enough, then test subjects it showed him.

The first time he tried the spell, the baby rabbit's brain literally exploded. Harry took one look at the gore and threw up. After hurriedly clearing his mind of any particular desire, the mess thankfully vanished. The mirror reverted to showing his family.

Harry made a decision: "Something less cute next time."

It was much less disturbing when the victim was a baby rat. Partly because of the Pettigrew association, partly because it was an ugly, hairless, Umbridge-pink creature. Still not _great_ , but at least he didn't lose what little was left of his breakfast when his second attempt also went awry.

* * *

It took Harry weeks of practice, working up from baby rats to progressively older and more complex animals, before he felt confident in his ability with the Memory Transfer Charm. Well, confident enough to use on an imaginary person in a mirror, anyway. He wasn't likely to risk it on a _real_ person, not unless he was okay with them possibly becoming brain damaged.

He was quite fortunate that the spell had the rescind option at the end, or who knew what sort of rubbish he'd have in his head by now. As it was, he was stuck with the instinctive understanding of 'lion equals DANGER!' after using the spell on an antelope and getting the ending wrong. It was a sensible enough instinct to have, he supposed, but a bit ironic given his Hogwarts house's mascot. He was grateful that it was only _actual_ lions and not also images of them that he was fearful of; it'd be hard to explain why he kept cowering from every lion-themed carving and trinket in the common room.

"Right," he said, eyes tightly closed and slipping into that now-familiar feeling of directed _desire_. "I _need_ to know how to defeat Voldemort. I _need_ to be a person that has done it."

Harry spent perhaps longer than necessary focussing on just that, but this _would_ be the biggest, most important illusion he'd ever conjure in the mirror … if it worked.

Hesitantly he peeked open one eye and then another. His breath escaped him in a whoosh of air.

The Harry in the mirror was a couple of years older and lot more worn around the edges. Despite his exhaustion however, despite the cuts and bruises and dirty, torn robes, there was joy and relief in his eyes. He looked like a man who had just had the weight of the world relieved from his shoulders.

"So far so good," he whispered. He licked his lips and raised his wand, focussing on just what knowledge he wanted to take away, and began the complex wand motion. " _Memoria Transfero!_ "

Harry stood gasping, staring with unseeing eyes, as he assimilated it all.

 _… prophecy … the one with the power … Horcruxes … splintered soul … Fiendfyre or basilisk venom … diary, locket, ring, diadem, cup … himself … blood of the enemy … tie to life … then he's mortal … one lucky shot …_

One last twist of his wand. Confirmation.

He knew. Harry knew now how to win. Or at least how to level the playing field.

* * *

Very early on Christmas day Harry woke from an odd, cloudy dream. Had he been flying or something?

He stared blankly at the bed canopy for a few minutes. Judging from the light, or lack thereof, it was even earlier than Harry usual woke these days. Still, that might be for the best, considering what day it was. Everyone would be up early and this would give him time to get back before they awoke.

Harry slipped from his bed and then from the tower. He shot the small pile of presents at the end of his bed a longing look as he went by, but promised to be back in time to open them with everyone else.

Ten minutes later Harry threw off his invisibility cloak as he stood in front of the Mirror of Erised. He closed his eyes and concentrated.

"I need to understand Potions, fourth year. _Memoria Transfero!_ "

When he was done, Harry blinked. His head felt just a little heavy, barely at all; he would be able to have another session later that evening. He turned to leave, done for the day. It had to be this way. Harry was being _extra_ careful not to overload his mind with new knowledge too quickly, still far too wary of the potential side-effects.

The first time he used the memory transfer spell to try and get ahead in his schoolwork, Harry had made the mistake of seeking the whole of a top graduating student's academic knowledge. As the information poured into his head an intense migraine had begun to develop. It was so cripplingly painful that he'd only _just_ managed to change the final wand movement and reject the transfer, leaving him to fall to the ground, gasping in relief as the pain faded.

Since that near-disaster, Harry stuck to a single year's worth of knowledge in a single subject for each morning session. He would then judge how heavy or clouded his head felt and whether he had any sort of headache. If the effect was minimal, he'd do another session in the evening. Otherwise he'd let it go until the next day.

In this manner he'd managed to work his way through the entire first through third year curriculum and was making headway in the fourth. It helped that he already _knew_ much of the information himself and the spell was only filling in gaps. That meant less knowledge in the transfer, which meant he could allow two sessions a day. Some subjects however, ones he'd never taken like Arithmancy and Ancient Runes, contained too much new information to risk more than a single session a day.

When Harry got back to Gryffindor Tower he was confused to find Ron missing. He wondered if he'd already gone down to breakfast. But no, Ron would have opened his gifts first if he had, and they were still waiting on the end of his bed.

"Maybe he went to see the twins?"

But a search of their dormitory revealed them missing too, gifts also left behind. Thoroughly confused, Harry wandered back to his own dorm to change for the day and headed to breakfast. He was stopped just outside the Great Hall by Professor McGonagall

"Mr Potter, a word." She led him to a nearby classroom and closed the door.

"What is it, professor?" he asked, wary, because she looked very grave for some reason.

"I'm afraid there's been an incident and the Weasleys have all left the school. They're staying at headquarters. You were called too, but as we couldn't find you …" She sighed heavily, pinching the bridge of her nose in what Harry numbly suspected to be an effort to hold back tears. "Perhaps it's best this way. The family will need time together."

"Professor, what's _happened?_ Why did they leave? Why do they need time?"

"Mr Potter. Harry. There was an incident, as I said, and Arthur Weasley … has been killed."

* * *

"How …" He trailed off and closed his eyes. Did he really want to do this? Yes, he needed to know. "How did Arthur Weasley die?"

He got his answers. And for the second time ever, Harry turned to the side and vomited in the mirror chamber. He blinked back tears as he Vanished the result. His back against the wall, he slumped down to the cold floor.

"Damn my curiosity," he whispered hoarsely. "I didn't need to know that."

No, he really didn't … especially not in such graphic detail.

Harry didn't need to know the way that Nagini's fangs had sliced through flesh, injecting venom which _burned like fire_. He didn't need to know how the serpent had attacked again and again, opening up wounds on Mr Weasley's arms as he raised them to fend the animal off, then in his _face_ when he grew too weak from the venom to defend himself anymore. He didn't need to know about the seizures that eventually followed, the way Mr Weasley had cracked the back of his head open as he flailed and slowly went still.

Harry hadn't needed to know any of that.

One thing was for sure though: Voldemort needed to be stopped, and soon, before more innocent people died.

* * *

It was disturbingly easy to sneak out of Hogwarts unnoticed. He just donned his invisibility cloak and crept down the tunnel behind the humpbacked witch, emerging in the basement of Honeydukes.

Once he had walked far enough that he was out sight of Hogsmeade and any villagers that were about, Harry removed the cloak and flourished his wand. A pause, and then—BANG!

"Welcome to the Knight Bus, emergency transport for the stranded witch and wizard …"

Harry gave a false name, stated his destination, paid his fare and boarded. He resisted the urge to touch his face, to make sure his charmed disguise was holding. He knew it was. He'd fully understood and comprehended the subject after a session with the mirror. Still, he worried. No one could be allowed to know that it was Harry Potter rather than a nameless adult wizard, albeit a slightly-short one, who called the Knight Bus today.

"Your stop, Mr Smith," the conductor called.

Harry nodded and exited. The bus vanished as loudly as it had appeared, leaving Harry alone on a neglected little country lane. He stood in front of a gate that looked about to fall apart. He pushed his way past it and on down a vague path until, from the gnarled and overgrown trees, a dilapidated shack appeared, overtaken by the forest.

"The Gaunt home," he whispered to himself. And then: " _Serpensortia_."

The Trace, which monitored underage magic, was surprisingly easy to remove from a person. Well, easy if one had access to the Mirror of Erised and a good enough imagination to realise its potential.

" _Sssss. What issss thissss?_ " the snake demanded, tongue flickering out to taste the air. " _Where am I?_ "

" _I have a job for you_ ," Harry replied in Parseltongue.

" _Do I look like your sssservant? Do it yoursssself, fleshling. Now take me back before I bitesss you_."

Harry sighed. He hadn't wanted to do this, but had practiced on mirror-snakes all the same, just in case. He swallowed hard and brandished his wand.

" _Imperio_. _This is what you will do …_ " Harry then explained his orders. " _The password is 'Long Live Lord Voldemort',_ " he finally said. " _Go._ "

Yes, it was only a snake, but something about that curse made him feel dirty.

Dark Arts.

He didn't like them one bit.

But what other choice was there in this situation? If he was to avoid the deadly Wasting Curse Voldemort placed on the ring, he needed the 'key'. And the key in this case was a serpent speaking the password. Any dark wizard could Imperius a snake to retrieve the ring, but only a Parselmouth could convey the right passphrase. It would have been the perfect protection … if not for Harry having been made an unintentional Horcrux and thus capable of the snake tongue as well.

It seemed like hours before the snake returned, but was probably only minutes. It had a ring threaded around one fang which it dropped before him. Harry quickly picked it up and tucked it away in the silk-lined bag he'd brought to contain the Horcrux's effects. Then he released the snake from his control.

It reared back at once, hissing, " _Enemy! I will HURT it for this impudencccce!_ "

Harry quickly Vanished it back from whence it came before it could make good on its promise.

The journey back to Hogwarts was uneventful. Before he climbed out from below the humpback witch statue, Harry dismissed his disguise and performed a few final spells.

" _Prior Incantato_ ," he cast several times, each followed by, " _Deletrius_."

Once evidence of his outing had been erased from his wand, everything from disguise to Unforgiveable, he nodded and tucked it away.

* * *

The diadem was much easier to acquire.

Despite the fact that he'd been using it all year for their illicit DA club, Harry had never thought to ask the Room of Requirement to show him all the things people had stored inside.

He wanted to get lost in the cathedral-like room filled with years, decades, perhaps even _centuries_ of lost items and things left behind. But he had more important things to do first, a Dark Lord to defeat. He promised himself to make time afterwards though.

Huh …

He was thinking about it like a foregone conclusion. Harry wasn't stupid; he _knew_ that even rendered mortal, Voldemort would be dangerous. But the mirror and the knowledge he gained from it had given him a confidence, a _hope_ that he'd never thought possible.

For the first time since watching Voldemort rise from that cauldron, Harry really, truly thought that he could not just fight, but _win_ the war.

* * *

The locket was a bit trickier. According to the mirror it was at Grimmauld Place, in one of those bin bags of junk from their cleaning spree that Sirius had thrown out the back door, but had yet to actually get rid of.

If he'd gone to Grimmauld Place with the Weasleys, Harry could have easily slipped away at some point to grab it. But McGonagall was right; they probably needed time together as a family to grieve. He didn't want to intrude on that by asking to go too. But on the other hand, he _needed_ to.

Fortunately, his dilemma was solved by Professor McGonagall.

"The funeral will be this afternoon," she informed him quietly after pulling him aside. "If you wish to attend …"

"Yes," Harry said at once, equally quiet. "Yes, of course."

"Then be ready after lunch and I'll take you to headquarters. You'll head out with the Weasleys from there. Pack for an overnight stay as well. I'll bring you back tomorrow."

He nodded.

* * *

Harry's heart raced, afraid that someone would notice him missing, or hear the rustling of the bin bags as he searched through them, and come looking. And then he'd have to explain … or come up with a convincing lie, at least.

Fortunately though, before either could happen, his hand made contact with an oval-shaped item about the size of a chicken's egg. Harry withdrew his hand and let a smile of success light his face. Then he quickly tucked the locket away in the silk bag and hurried back inside as if he'd never left.

* * *

The funeral was as dismal an affair as Harry had expected. Stood by an unusually restrained and solemn Padfoot, he tried not to cry when Mrs Weasley broke down mid-service in wrenching sobs, supported between Bill and Charlie.

A lot of people turned out: Hermione was there, all of the Order, several Hogwarts professors, Ministry workers and more besides. Mr Weasley might not have been an important, influential man, but he was a good one; friendly, kind, personable … just _decent_. A lot of people felt the need to pay their respects.

Percy had showed up at the start of the funeral, pale-faced and shaky with red-rimmed eyes and an uncertain expression. It was not a day for holding grudges, and no one objected when Mrs Weasley hugged him tightly and pulled him in amongst the rest of the immediate family. It had taken a terrible catalyst, but finally the family split was mended. Percy spent the service with an arm around Ron's shoulders and Ginny clinging to him. The twins, of course, clung to one another.

Back at Grimmauld Place afterwards, Harry and Hermione somehow ended up sharing a bed with Ron, all three of them curled together like a pile of puppies, offering him their support.

"I'm so sorry, Ron," Hermione whispered tearfully.

"Yeah," Ron said, speaking for the first time that day. His voice was hoarse and scratchy, like he'd been crying a lot lately. Which, of course, was probably the case. "Thanks for being here you guys."

"Where else would we be?" Harry asked.

They fell asleep together. Harry stirred only once, when Mrs Weasley came to check on them.

"Go back to sleep, Harry," she said quietly, laying a blanket over them all. "My Ronnie's lucky to have two such good friends."

Harry nodded and lay back down, eyes falling shut again on the image of her wiping tears from her cheeks as she left the room.

* * *

"—can't find him," a dull voice pronounced.

Harry froze, making sure his invisibility cloak covered his feet, and drew back into an alcove. Was that … Goyle?

"I'm telling you, you oaf," Malfoy's voice snapped, "Potter's _definitely_ been disappearing _somewhere_ up here. Now stop telling me 'can't' and keep looking! I want to know what he's up to."

Twin grunts signalled Crabbe and Goyle obeying.

Harry retreated back into Fluffy's chamber as quietly as possible. He locked the door and fled back to the Mirror of Erised where he paced back and forth before it, worrying.

Clearly he had been too careless if Malfoy had caught on that he was up to something in this part of the castle. Harry could remember a few times he'd not bothered with the cloak, thinking no one was about.

"Stupid," he hissed under his breath. "How could I be so _careless?_ "

With Malfoy nosing around, the mirror was at risk. What if he figured out, as Harry had, just how priceless an artefact it was? Imagine if Voldemort's side got access to such an easy source of endless knowledge. It would be a disaster! He had to do something, tell a teacher and—

Harry froze. No, he couldn't. If he told McGonagall or Dumbleodre they would take the mirror and hide it, depriving Harry of his best weapon against Voldemort. There had to be an alternative. There _had_ to.

Clenching his fists, Harry stopped in front of the mirror and focussed.

"I need a way to hide you. I _need_ to know that no one else will find you or steal you away from me." The image blurred, his parents and Sirius fading. Alone now, his reflection nodded confidently at him. " _Memoria Transfero_."

With a Shrinking Spell that could be used even on powerful artefacts like the Mirror of Erised, Harry could take the mirror with him. The Fidelius Charm, meanwhile, would hide it from all eyes but his own. It could never be stolen away then.

The mirror was _his_. He would keep it safe.

* * *

Apparently goblins didn't share the habit of wizards in overlooking House-Elves. Harry had felt quite clever at first when he considered simply asking Dobby to fetch Hufflepuff's Cup, but after consulting with the mirror he learned it would not work.

What _would_ work, according to the mirror, was a method the goblins hadn't overlooked, so much as been unable to find a way to guard against. Normally it wouldn't matter. After all, phoenixes were beings of light and righteousness; they wouldn't steal from Gringotts, nor would they help a human to do the same … under ordinary circumstances.

"… and he trusted this Horcrux to his follower, Bellatrix Lestrange, who hid it away in her Gringotts vault. I need to get that cup and destroy it to defeat Voldemort. So, will you help?"

Fawkes considered his plea for a long moment before coming to a decision. He bobbed his head and whistled in an affirmative sort of way, and Harry sighed in relief. Apparently not one to waste time, Fawkes immediately disappeared in a fireball causing Harry to jump back in shock. A few moments later however, the phoenix reappeared with a small golden cup in one claw.

Fawkes was quick to drop the object, ruffling his feathers and making a harsh cawing sound at it. Harry was sympathetic. If even he, a mere human could feel the oily _wrongness_ of a Horcrux, then it must be a hundred times worse for a phoenix. Not for the first time Harry was so incredibly grateful that his mother's magic kept the one in his head contained.

He quickly gathered the cup up in a silk bag. As he drew the drawstring tightly shut, Fawkes settled.

"Thank you," Harry told the bird, who replied with a trill of triumph. "Yes, we're going to beat him. We're really going to do it. That was the last one I needed to get my hands on."

* * *

With all the Horcruxes collected there was only one thing to do.

The Chamber of Secrets was as damp, dark and miserable a place as he remembered. The basilisk corpse was still there, surprisingly well-preserved. The one fang that had broken off in Harry's arm was discarded nearby. It lay next to a stain of ink-black and blood-red.

The Horcruxes came alive as they realised they were to be destroyed. They tried to tempt him and to turn him away with words and images and a mental sort of urging, but Harry remained strong and determined. He brought the fang down on the items one by one, grimly satisfied each time an object warped and screamed and was destroyed.

And then he was done. All the Horcruxes were destroyed … except for one.

Harry raised a hand to his forehead and traced his scar. He swallowed hard and hoped he'd have the courage to finish it. No, he _knew_ he would, because nothing else was acceptable. He would face his fear, he would die as he must, and he _would_ come back to live out the rest of his life. The mirror had shown him it was possible and Harry trusted in that.

* * *

Harry could pass his NEWTs tomorrow. Not just pass, but receive straight O's. In all available subjects.

With a bit of training to improve his physical condition he could be accepted as an Auror. No, a _Hit Wizard_.

All but one of the Horcruxes was destroyed and, according to the mirror, if his greatest _desire_ was to confront Voldemort he need only linger around the Ministry Atrium this evening.

Harry was as prepared as he could hope to be.

It was time to gather his courage and face his destiny.

* * *

Harry was hidden under his invisibility cloak, hiding in a corner of the Atrium. He only noticed the disillusioned Death Eaters heading for the elevators because he'd know they would be there. They disappeared deeper into the bowels of the Ministry, and time passed. Harry waited patiently.

A few hours later there was a sharp _CRACK!_ as Voldemort himself Apparated into the Atrium with a look of confusion and frustrated impatience on his face. Probably he was wondering why Harry hadn't reacted to the dream vision he'd sent. It surprised Harry a bit, this confirmation that Snape really was on the side of light; if he wasn't, he would have told Voldemort about Harry's success with Occlumency.

Harry took a deep breath and steeled his nerves.

He flung back his cloak.

"Voldemort," he said, voice trembling the slightest bit, and slipped a hand into his pocket.

The Dark Lord spun around, his reflexes amazingly sharp, and cast an " _Avada Kedavra!_ " before Harry could react.

Not that he intended to.

No, he didn't try to dodge, just watched that terrible green light speed towards his face until it enveloped his vision and—

Harry Potter died.

* * *

Harry blinked his eyes open and looked around in bewilderment. He was … in the mirror chamber? Or, well, the chamber as it would look all in shades of white and beige. The Mirror of Erised stood in the centre of the room, shining brightly as if under a sunbeam or a spotlight, obscuring the reflection.

He was confused and more than a bit alarmed, because last he knew that mirror was shrunken down in his pocket, safe and sound. His hand flashed down to his trousers to check … only to find them missing.

"Naked," he choked out.

He suddenly wished that the mirror could create actual, physical things he desired, not merely reflections of them. No sooner had the thought crossed his mind than did a pale robe shoot out of the glassy surface.

Harry hurriedly dressed, even as he wondered what was going on. Once he was no longer baring it all to the world, he squinted and leaned closer to the mirror, trying to see his reflection. The light which illuminated it was too bright to make anything out.

"Hello, Harry."

Harry spun around and gaped. Stepping through the door to the potions' puzzle room was none other than—

" _Mr_ _Weasley?_ "

"The one and only." The man gave him a sad smile. "Ah, Harry. No offence, but I'd hoped not to run into you here for a good, long while. You _or_ anyone else I care for."

"Where is 'here', exactly?"

Mr Weasley looked around. "Well, it's different for everyone. I see a little bakery that used to be open in Diagon Alley. Long gone now, but I'll always remember it well. It was the first time I saw my Molly." He smiled warmly. "We were just ten years old, not even at Hogwarts yet, but I was instantly smitten. What about you? What do you see?"

"Um … a room in Hogwarts."

"Not too surprising," Mr Weasley reflected.

"That still doesn't explain where we are."

"From the few folk I've run into, I understand it to be a … waiting area of sorts."

"Waiting area?"

"We still need to be processed before we can 'move on'." Mr Weasley rolled his eyes. "Even in death I can't escape bureaucracy. I loved my job, but that was always the worst part of it."

Harry huffed out a not-quite-laugh. This was a lot to take in.

"What happened, Harry?" Mr Weasley asked. "It hasn't been that long and already you're here …"

"Voldemort. Oh, no, don't be upset," Harry added hurriedly. "It's only temporary."

Mr Weasley's face was pained as he said, very gently, "Harry, I'm afraid there's no way—"

"It's complicated. Something about a Horcrux, a sliver of Voldemort's soul in my scar. That and a connection between us because he used my blood in his resurrection. It's a one-off, chance-in-a-million type of thing, but I can go back."

"A piece of Voldemort's soul?" Mr Weasley looked aghast. Then his gaze fell on something. "Is that what _that_ is?"

Harry looked down and recoiled in disgust. In a corner of the room was an ugly, flayed, foetus-like form, curled up and struggling weakly. How had he missed that? He could only suppose he'd been too distracted by the mystery of the mirror.

"I think it must be," Harry whispered in horror.

"Well," Mr Weasley said, "best stay away from it."

"Yes," Harry agreed, nodding his head emphatically.

"And best you get back too, if you're going. Who knows what leaving your body soulless for too long could do."

Harry's mind flashed to Muggle-learned knowledge of the effects of oxygen deprivation and permanent brain damage. But didn't Dementor-Kissed bodies keep on breathing and living, even without a soul? Still, best not to take any risks. He was ready to go back.

"Good bye, Harry," Mr Weasley said as a white mist descended in the room, slowly hiding him from view. "And good luck."

* * *

The first thing he heard was screaming.

"He moved!"

"Oh Merlin have mercy, he's getting up!"

"He's _alive!_ Run! Run, he's alive!"

Apparently someone had put out the alert that something was awry and people had come to investigate. Harry could imagine their horror on discovering the supposedly-still-dead Voldemort was not only very much alive, but also present in the Ministry Atrium.

A small, mean part of Harry thought they deserved the unpleasant shock after a year of branding him a liar and a dangerous lunatic. Not to mention the horror that was Umbridge, sent to Hogwarts to shut him up. Harry had suffered half a dozen of her detention-cum-torture sessions. They'd only come to a stop when he discovered the potential of the Mirror of Erised and decided that defying her wasn't worth the effort; it just wasted time that could better be spent with the mirror. Umbridge had seemed disappointed by his sudden good behaviour and refusal to rise to the bait, only confirming his suspicions that she was a sadist. For siccing that woman on him, wizarding Britain _deserved_ a bit of unpleasantness in turn. Maybe that was petty, but Harry was only human.

Meanwhile, Harry was a bit confused by the _content_ of the shouting. 'He moved'? 'He's getting up'? Had Harry not been the only one to briefly fall? Had Voldemort also visited the 'waiting area', as Mr Weasley put it?

"Oh, Tom," Dumbledore said in a voice heavy with grief. "What have you done?"

Apparently the headmaster had also shown up. It occurred that the man was probably upset about _Harry's_ supposed death and he should really do something about that.

Harry blinked his eyes opened and rolled to his feet.

There was more screams and some sighs of relief and even cheers.

"He's alive!" someone shouted, but the words were much more joyful this time.

"The Boy Who Lived will save us!" someone else declared.

Harry was a bit put out at them putting all the pressure on his shoulders like that. He was just an average fifteen year old boy albeit with a _far_ -from-average history. Fortunately for Harry's sanity, he _could_ in fact save them all.

Maybe.

He hoped.

Well, the Mirror of Erised had given him an advantage anyway.

Voldemort's face was one of disbelief that Harry had survived a Killing Curse _again_. Then it turned to one of fury and frustration as he raised his wand. This time though, Harry was both ready and willing to react.

" _Avada Kedavra!_ "

" _Expelliarmus!_ "

Just as had happened a year ago in the graveyard, their spells connected and their brother wands wove a cage of golden magic around them, preventing anyone from interfering. Beads of light pulsed along the thread between them, but Harry didn't bother forcing them to Voldemort's wand this time. No, this was just a distraction. Let _Voldemort_ try to overpower _him_ this way, while Harry—

He withdrew a wand he'd found in the Room of Hidden Things. It was not a perfect match, but good enough for his purposes.

" _Diffindo_ ," he grunted, giving it all the power he could.

The connection between wands snapped and the cage shattered as Voldemort's head was cut from its body. It bounced once, twice, then rolled to Harry's feet staring up at him in frozen, uncomprehending horror as Voldemort's body collapsed where it stood.

There was a long moment of silence, and then—

The crowd burst into wild, hysterical cheers.

He'd done it, he _really_ done it. Harry had fulfilled the prophecy and Voldemort was no more.

And it was all thanks to the Mirror of Erised: the 'power the Dark Lord knows not'.

* * *

If Harry was expecting peace and quiet now that Voldemort was gone, he was horribly disappointed. Apparently defeating the Dark Lord for a second time, and so publicly at that, had rocketed his fame to whole new levels. He was inundated with letters, his schoolmates wouldn't stop staring and whispering, girls practically stalked him and reporters repeatedly tried to break into Hogwarts for an interview.

It was too much. Harry didn't want the awe and praise of so fickle a public. He didn't want awe and praise at all, to be honest. He just wanted to be normal. He always had. He wanted to be _left alone_. Few people would grant him that that however, so Harry took to hiding away whenever possible. Eventually he even had to resort to Fideliusing an unused classroom just to get some privacy.

The one upside of being driven to such extreme isolation was that Harry could spend more time with the Mirror of Erised. Having absorbed a full Hogwarts education and more besides, Harry had branched out into more esoteric areas of study. The deepest, most compelling mysteries of magic and the universe unravelled before him. He was really beginning to understand the Ravenclaws; there was so much to learn and it was so _interesting_.

* * *

Harry was exploring a distant nebula never seen to human eyes, not even dreamed of.

Harry stared into the Mirror of Erised, swaying to an unheard tune.

A yawn interrupted, and he tried to resist, but he was _so tired_. Just a little nap couldn't hurt. A short one. It had been a while since slept … or moved, or did much of anything expect stare into the mirror really. When did he last eat? It didn't matter; he wasn't hungry. But he was _tired_.

His body slumped to the floor, curled up before the mirror, eyes grudgingly fluttering closed. Harry didn't notice how, as his desire wavered, the stars faded to reveal a new image. Unlike in times gone by it wasn't his parents and godfather that appeared. Instead it showed Harry, just Harry, exactly as he was, lying before the mirror.

* * *

When his eyes opened Harry was in the old mirror chamber, but it was pale and bright. He didn't notice the changes. He didn't even notice his lack of clothing. He just turned his eyes back to his reflection and conjured a new desire.

There was so much more to learn.

* * *

 _"Men have wasted away before it, entranced by what they have seen …"_  
– Albus Dumbledore, on the Mirror of Erised

* * *

 **More author's notes:**

Please don't kill me for the ending? Or, you know, if the urge is really overwhelming then just ignore everything after Voldemort's defeat and imagine a 'happily ever after' instead.

Also, title comes from the quote: "A little knowledge is a dangerous thing. So is a lot." Which is from … somewhere? I googled it and I'm still not sure: either Alexander Pope, Einstein or Encyclopaedia Britannica apparently. The latter also adds "The more you know, the more you need to know" to the end, which is super fitting for this.

* * *

 **Reviews make me happy (hint, hint).**


End file.
